The screening and diagnosis of cervical squamous intraepithelial lesions has both important clinical and public policy implications. In the United States, approximately 50 million women could be screened for cervical cancer each year; in addition, approximately 3 million women have further evaluation because of an abnormal result at the time of screening. However, current cervical screening and diagnosis methods, as well as methods for cervical cytological and pathological evaluation, have been challenged for their effectiveness and economic consequences. The goal of Project 5 of the Program Project is to test hypotheses which evaluate the effectiveness and cost-effectiveness of strategies for the screening and diagnosis of cervical precancer, including point-probe optical spectroscopy, multispectral digital colposcopy, a combined device incorporating the point probe and multispectral digital colposcopy, a battery-powred diagnostic imaging aid (DIA) optimized for use in the developing world, an in vivo confocal microscope, the use of contrast agents to improve diagnosis, and automated quantitative cytology. Over the last nine years, our clinical trials have included the collection of real time cost data from the US and Canada, and we plan to extend this data collection, eventually, to Nigeria. Receiver operating characteristic (ROC) curve analysis will be performed to evaluate the effectiveness of diagnostic and screening technologies for cervical squamous intraepithelial lesions. Effectiveness will be evaluated by visual comparisons of the ROC curves and areas under the ROC curve for the various strategies. We will modify our existing decision-analytic models based on analyses of data previously published in the literature as well as primary data collected from other trials in this Program Project. Cost-effectiveness analyses will be performed using the societal perspective, to determine the incremental cost-effectiveness ratios, measured in dollars per quality-adjusted life year, of various strategies to screen, diagnose, and manage cervical precancer in the US, Canada, and eventually Nigeria. The results from this Project will be used to enhance the development of cervical screening and diagnosis methods in companion Projects. In addition, these results can provide policy and decision-makers information regarding the effectiveness and cost-effectiveness of emerging technologies for screening, diagnosis, and management of cervical precancer.